The present invention relates to an electronic instrument for counting and totalizing a plurality of different types of blood cells or other biological cells and expressing the individual cell counts as a percentage of the total count.
Differential cell counts are an important aspect of testing in medical and other biological laboratories. A white blood cell differential is one of the most commonly performed counts. Other differential counts include maturation index in PAP smears, leukocyte alkaline phophatase, and barr body counts.
The apparatus currently employed by laboratories for computing hematological differantials and other cell counts are mechanical counters or electrically operated mechanical step counters. These range from very simple counters which are capable of providing running totals of two types of cells to counters which are capable of totalizing nine different types of cells as well as a total of all cells counted. In order to express the individual cell counts as percentages of the total, which is the most commonly used method for rendering a meaningful expression of the cell counts, is to terminate the count when the total of all cells counted reaches 100. At this point, the individual percentages are equal to the total count expressed for each of the cell types. A problem which often arises, however, is that the technician may not stop when the total count reaches 100 thereby necessitating manual computation to determine the percentage value for each type of cell. This is a time consuming operation and often causes technical errors. This may result in an erroneous cell differential leading to an incorrect diagnosis on the part of the physician utilizing the laboratory data.
A further disadvantage to the necessity for terminating the count at 100 cells or ten factor multiples thereof is that it may be desirable for all the cells on a certain slide to be counted. In this case, it is imperative that the percentage calculation be made.
The mechanical counters are cumbersome to operate and may fail to register an intended entry. Additionally, many of the mechanical counters do not provide means for deleting an erroneously entered count. Many counters have no means for preventing the simultaneous entry of two individual counts leading to another source of inaccurate entries.
By necessity, the prior art counters employ intricate mechanical components and are therefore costly to manufacture and require a certain amount of maintenance to enable them to operate smoothly and accurately. Mechanical components also impose certain size and weight contraints on the apparatus as well as power requirements where the mechanical registers are actuated by electromechanical devices.
It is therefore, an object of the present invention to provide an electronic calculator-register which is capable of providing running totals of individual cell counts as well as a total cell count and means for calculating the percentage of the individual counts to the whole at any time during the count.
It is also an object of the present invention to provide a calculator-register for cell differentials wherein the running totals and the individual cell percentages are conveniently displayed.
It is a further object of the present invention to provide a calculator-register for cell differentials which is of solid state construction employing a minimum of mechanical elements thereby resulting in a unit which is small in size and highly responsive and reliable in its operation.
A further object of the present invention is to provide an electronic calculator-register capable of rapidly and accurately providing individual cell percentages by means of simple keyboard entries regardless of the total cell count.
Another object of the present invention is to provide an electronic calculator-register for cell differentials wherein double count entries are prevented.
Yet another object of the present invention is to provide an electronic calculator-register for cell differentials which permits easy deletion of incorrectly entered counts.
A still further object of the present invention is to provide an electronic caculator-register for cell differentials including audible means for signaling the technician when a single cell count has been entered and for providing a different audible signal when 100 counts have been entered.
Yet another object of the present invention is to provide an electronic calculator-register for cell differentials which can be economically mass manufactured at a low unit cost.
These and other object of the present invention will be apparent from the detailed description together with the appropriate drawings.